Gunning Transceiver Logic

(GTL) A
standard for electrical signals in CMOS circuits used to
provide higher data transfer speeds with smaller voltage
swings [compared with what?].

The GTL signal swings between 0.4 volts and 1.2 volts with a
reference voltage of about 0.8 volts. Only a small deviation
of 0.4 volts (or thereabouts) from the reference voltage is
required to switch between on and off states. Therefore, a
GTL signal is said to be a low voltage swing logic signal.

Gunning Transceiver Logic has several advantages. The
resistive termination of a GTL signal provides a clean
signalling environment [what?]. Moreover, the low terminating
voltage of 1.2 volts results in reduced voltage drops across
the resistive elements. GTL has low power dissipation and can
operate at high frequency and causes less electromagnetic
interference (EMI).